Autism Spectrum Disorder (ASD) encompasses a group of complex disorders of brain development. These disorders are characterized, in varying degrees, by difficulties in social interaction, verbal and nonverbal communication and repetitive behaviors. These disorders include, but are not limited to, autistic disorder, childhood disintegrative disorder, pervasive developmental disorder-not otherwise specified (PDD-NOS), and Asperger syndrome. ASD affects 1-2% of predominantly male individuals. ASD is an enormous medical and economic problem in the United States and, at present, there is no approved, mechanism-based treatment.